Mankind has long used various shapes and sizes of sticks as supportive aids in their mobility. Over the past century or so, what is today commonly called a crutch has evolved into more specialized shapes. Those devices that are currently considered as traditional crutches aid mobility, but their design and use may also contribute to the development of significant medical problems.
As these walking aids have evolved, the primary focus appears to have followed the following design objective: reduce the cost of manufacturing to enhance mass production and marketing capabilities. The previous designs for walking aids have lacked ergonomic design objectives addressing medical problems related to the disabilities and have failed to reduce or eliminate these problems.
Three specific medical problems resulting from using the traditional crutch are: (1) injury from loss of traction, (2) carpal tunnel syndrome, and (3) neuropathy. While the first of these problems may be obvious to the general public, the other problems are not as obvious. Carpal tunnel syndrome is a painful or numb condition of the wrist and hand resulting when tissues that form a tunnel-like passage in the wrist swell and pinch a nerve within the passage. Repetitive movement, as in typing or knitting, often causes this condition.
The handle of a typical crutch is generally round like a dowel, which offers little, if any resistance to rotation of the hand and wrist. Because medical practitioners recommend using the handle to provide principal support for the body weight, rather than the shoulder supports, this using of the handle places abnormal pressure on the forearms, hands and wrists of the user. Without adequate and proper stability for these members, carpal tunnel syndrome may result from long-term use of the typical crutch.
Neuropathy is any disease to the nervous system. In the case of long-term crutch users, the term neuropathy describes damage to nerves in the shoulder or underarm area resulting from use of the traditional crutch. Carrying the body weight on the shoulder support, unfortunately, is quite common. A significant contributing cause of neuropathy is attributed to this abnormal pressure and to the shoulder absorbing repeated impact when the crutch makes contact with the supporting surface.
According to the U.S. Census Data, the total number of people in all age groups in the U.S. with disabilities is about 51 million. U.S. Census Bureau, June-September 2002 Data from the Survey of Income and Program Participation. Of those 51 million people, about 9.1 million people use a walker, a crutch or a cane. Id. Thus, there is a large population that may benefit from improvements in the design of walking aids. The incidence of injury from loss of traction, carpal tunnel syndrome, and neuropathy within these groups indicates that the medical problems associated with use of traditional crutches have not been adequately addressed in the design of walking aids.
Once adjusted for a particular user, the traditional crutch is designed to have a single configuration. That configuration has a fixed length, which becomes a problem when navigating a changing environment, such as stairs, curbs, restaurants, and other obstacles.
It is to solving these and other problems that the present invention is directed.